>>4 http://en.wikipedia.org/wiki/Who_is_a_jew In general, Orthodox Judaism considers individuals born of Jewish mothers to be Jewish, even if they convert to another religion.[35] Judaism also views as Jewish those who involuntarily convert from Judaism to another religion (Hebrew: anusim (אנוסים), meaning "forced ones"); and their matrilineal descendants are likewise considered to be Jewish. A Jew who leaves Judaism is free to return to the faith at any time. In general, no formal ceremony or declaration is required to return to Jewish practices.